7 Jun
2013
7 Jun
'13
1:14 p.m.
Hi Jiang.
Sorry, I missed that you'll use only receivers.
So, no any problems in this case.
Best regards,
Andrey Sviyazov.
(Sent from my mobile client)
07.06.2013 14:54 пользователь "Andrey Sviyazov" <andreysviyaz(a)gmail.com>
написал:
Hi Jiang.
Please remember that Rx and Tx of LMS can't work well at the same
frequency due to PLL's problems.
Also, please do not forget about TxLO leakage which is quite significant.
Best regards,
Andrey Sviyazov.
(Sent from my mobile client)
07.06.2013 14:36 пользователь "jiangwy" <wyjiang(a)ljshuoda.com> написал:
**
OK.
Thank you and Sylvain very much!
------------------------------
jiangwy
*From:* Alexander Chemeris <alexander.chemeris(a)gmail.com>
*Date:* 2013-06-07 18:12
*To:* wyjiang <wyjiang(a)ljshuoda.com>
*CC:* UmTRX <umtrx(a)lists.osmocom.org>
*Subject:* Re: Time to Switching Frequence
Jiang,
It's not tested. LMS6002D chip by itself has quite short tuning time,
but the current host and FPGA code introduce significant delay. I
can't find exact numbers regarding LMS tuning time, but IIRC it was
shorter than a GSM timeslot.
So, as Sylvain said, given software limitations it's easier to use two
channels of UmTRX to receive on two frequencies.
On Fri, Jun 7, 2013 at 11:21 AM, jiangwy <wyjiang(a)ljshuoda.com> wrote:
Hi All,
I have a project to monitoring ( air sniffer )
the data between GSM BTS and
MS using UmTRX.
Uplink Transmission is delayed 3 slots than downlink from specification.
So when I sync. with BTS and get the downlink
slot data, I must switch the
freqs of receiver from downlink to uplink in less than 2 slots.
When the program call
'usrp_dev->set_rx_freq(wFreq)', How much time does the
UmTRX switch to the 'wFreq' ?
Thanks in advance.
________________________________
Jiang WenYi
--
Regards,
Alexander Chemeris.
CEO, Fairwaves LLC / ООО УмРадио
http://fairwaves.ru